Glycerol (meth)acrylate carboxylic ester having a long shelf life

ABSTRACT

The present invention describes storage-stable glycerol (meth)acrylate carboxylic esters and a method for preparing these esters.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is US national stage of international application PCT/EP2017/079124, which had an international filing date of Nov. 14, 2017, and which was published on Jul. 26, 2018. The application claims priority to EP 17152399.6, filed on Jan. 20, 2017.

The present invention describes storage-stable glycerol (meth)acrylate carboxylic esters and a method for preparing these esters.

Methods for preparing glycerol (meth)acrylate carboxylic esters are known from the prior art.

Glycerol dimethacrylate is prepared from glycidyl methacrylate and methacrylic acid in the presence of catalytic amounts of a quaternary ammonium salt (in the specific case this is benzyltriethylammonium chloride).

The prior art describes methods for preparing glycerol dimethacrylate from methacrylic acid and glycidyl methacrylate in the presence of catalysts. It is preferable to use quaternary ammonium salts as catalysts.

<2 percent of unconverted glycidyl methacrylate remain in the product mixture in this reaction. It is known that glycidyl methacrylate exhibits genotoxicity in in vitro tests (OECD SIDS report “Glycidyl methacrylate”, 2000).

EP 0054700 describes a method for preparing glycerol dimethacrylate. Here, glycidyl methacrylate is added to a mixture of methacrylic acid, benzyltriethylammonium chloride and p-methoxyphenol at a temperature of 80° C. After work-up with sodium carbonate solution, phase separation and drying, the mixture is subjected to a fractional distillation. The yield is only 75%. In addition, the product polymerizes as a result of the purification by distillation. The distillation can therefore only be carried out with small amounts which is not economically viable for an industrial scale reaction.

WO2015/124458 discloses a process for preparing high-purity glycerol dimethacrylate. It describes the use of an acidic adsorbent for the post-treatment (purification) of a glycidyl methacrylate-containing glycerol dimethacrylate which was prepared in accordance with EP 0054700.

EP 1693359 describes the preparation of hydroxyalkyl (meth)acrylates. In this case, epoxide group-containing compounds are reacted with carboxylic acids in the presence of Lewis acids which each bear at least one directly bound di(cyclo)alkylamino group. The examples show that the product was found in the GPC up to at most 80 area %. An additional method step is also described which is intended to bring the epoxide content below 0.2% by weight. The Lewis acids used are uninteresting for industrial scale reactions since they are obtainable on the world market only in small amounts at high prices.

CS 200395 describes a method for preparing a monomer mixture by reacting (meth)acrylic acid with glycidyl (meth)acrylate in the presence of hydroquinone and triethylamine. The subsequent multi-stage purification includes an extraction with an aqueous alkali metal carbonate solution and subsequent extraction with an aqueous sulfuric acid and finally an extraction with water.

WO2005090281 describes a dental material comprising a (meth)acrylic acid and compounds with salicylic acid structure which are crosslinked with di-, tri- or higher valent compounds. 4-Hydroxysalicylic acid is reacted with sodium hydroxide and glycidyl methacrylate. The para-linked addition product of 4-hydroxysalicylic acid and glycidyl methacrylate is formed at only 20% yield.

WO0059982 describes a method for preparing highly crosslinked polyesters in which polycarboxylic acid anhydride is reacted with a polyol in the presence of an amine and the resulting acid is reacted with glycidyl (meth)acrylate or allyl glycidyl ether. This product is subsequently reacted with an anhydride.

EP951896 describes a method for preparing two-component and multi-component free-radically polymerizable dental materials. After the reaction of acrylic acid, mercaptoethanol and a radical initiator, half of the oligocarboxylic acid obtained is further reacted directly with glycidyl methacrylate. On account of the large excess of acid, there is no disproportionation.

On storage of glycerol dimethacrylate, disproportionation of the product may occur. In this case, glycerol monomethacrylate and glycerol trimethacrylate are formed.

It was an object to provide storage-stable glycerol (meth)acrylate carboxylic esters and a method for preparing storage-stable glycerol (meth)acrylate carboxylic esters.

The object was achieved by storage-stable glycerol (meth)acrylate carboxylic esters of the formula (I)

where R₁=H or CH₃, R₂=hydrogen, or aliphatic carbons with C1 to C30, or aliphatic cyclic carbon compounds having a ring size of C4 to C8, unsubstituted or substituted by N, S, O or P, or halogenated aliphatic carbon compounds with C1 to C8, or aromatic carbon compounds, or heteroaromatic carbon compounds substituted by N, S, O or P, or unsaturated aliphatic carbon compounds with C2 to C30 characterized in that carboxylic acids of the formula (II) endogenous to the system

where R₂=hydrogen, or aliphatic carbons with C1 to C30, or aliphatic cyclic carbon compounds having a ring size of C4 to C8, unsubstituted or substituted by N, S, O or P, or halogenated aliphatic carbon compounds with C1 to C8, or aromatic carbon compounds, or heteroaromatic carbon compounds substituted by N, S, O or P, or unsaturated aliphatic carbon compounds with C2 to C30 and optionally carboxylic acids of the formula (III)

where R₃=hydrogen, or aliphatic carbons with C1 to C30, or aliphatic cyclic carbon compounds having a ring size of C4 to C8, unsubstituted or substituted by N, S, O or P, or halogenated aliphatic carbon compounds with C1 to C8, or aromatic carbon compounds, or heteroaromatic carbon compounds substituted by N, S, O or P, or unsaturated aliphatic carbon compounds with C2 to C30, individually or in mixtures and optionally any further Broensted acids foreign to the system are present in sum total at a molar excess to the glycidyl (meth)acrylate present.

The term acids in accordance with the invention includes both carboxylic acids of the formula (II) endogenous to the system and carboxylic acids of the formula (III) and mixtures thereof, but also Broensted acids foreign to the system. Carboxylic acids (II) endogenous to the system include carboxylic acids which react with glycidyl (meth)acrylate to give the glycerol (meth)acrylate carboxylic esters (I).

The molar excess of the sum total of the acids in the storage-stable glycerol (meth)acrylate carboxylic esters includes both the presence of the carboxylic acids (II) endogenous to the system alone in excess, and any desired acid mixtures.

For example, a carboxylic acid or mixtures of different carboxylic acids according to formula (III) may be present in sum total in molar excess. A further alternative provides any Broensted acids alone or in mixtures, but also in mixtures with carboxylic acids of the formula (II) endogenous to the system and/or carboxylic acids of the formula (III) and mixtures thereof.

The molar excess of the acids in sum total in accordance with the invention is in a molar ratio of the acids to the glycidyl (meth)acrylate present of from 1.001:1 to 5:1.

Preference is given to storage-stable glycerol (meth)acrylate carboxylic esters having a molar ratio of acid to glycidyl (meth)acrylate in a ratio of from 1.01:1 to 2:1, particularly preferably in a ratio of from 1.02:1 to 1.5:1.

The ratio in accordance with the invention of acid to glycidyl (meth)acrylate is preferably present at the end of the addition of the reactants carboxylic acid (II) endogenous to the system and glycidyl (meth)acrylate.

Alternatively, this ratio is present also after the synthesis, i.e. prior to storage.

It has been shown that, prior to storage, the ratio can be adjusted by the addition of both the carboxylic acid according to formula (II) endogenous to the system and with carboxylic acids of the formula (III) foreign to the system or inorganic Broensted acids foreign to the system.

Particular preference is given to a storage-stable glycerol (meth)acrylate carboxylic ester characterized in that the carboxylic acid endogenous to the system is a (meth)acrylic acid with a molar ratio of (meth)acrylic acid to glycidyl (meth)acrylate of from 1.01:1 to 2:1.

The object was also achieved by providing a method for preparing storage-stable glycerol (meth)acrylate carboxylic esters. The method in accordance with the invention is characterized in that carboxylic acids of the formula (II) endogenous to the system

where R₂=hydrogen, or aliphatic carbons with C1 to C30, or aliphatic cyclic carbon compounds having a ring size of C4 to C8, unsubstituted or substituted by N, S, O or P, or halogenated aliphatic carbon compounds with C1 to C8, or aromatic carbon compounds, or heteroaromatic carbon compounds substituted by N, S, O or P, or unsaturated aliphatic carbon compounds with C2 to C30 and glycidyl (meth)acrylate are reacted at temperatures of 20-130° C. in the presence of a catalyst, by initially charging carboxylic acid (II) endogenous to the system and adding glycidyl (meth)acrylate continuously, and optionally adding carboxylic acids of the formula (III)

where R₃=hydrogen, or aliphatic carbons with C1 to C30, or aliphatic cyclic carbon compounds having a ring size of C4 to C8, unsubstituted or substituted by N, S, O or P, or halogenated aliphatic carbon compounds with C1 to C8, or aromatic carbon compounds, or heteroaromatic carbon compounds substituted by N, S, O or P, or unsaturated aliphatic carbon compounds with C2 to C30, individually or in mixtures and/or optionally adding any further Broensted acids foreign to the system in sum total at a molar excess to the glycidyl (meth)acrylate present.

It has been found that a distinctly improved storage stability can be achieved by suppressing the disproportionation by targeted adjustment of the ratio of the residual contents of acid and glycidyl (meth)acrylate in the end product.

A product is storage-stable for the time in which it is still able to maintain the specified product specification after storage at 30° C. or higher. This is defined by the content of disproportionation products not exceeding a maximum value when stored at specified temperatures, for example at 30° C. or 50° C. At the same time, diesters must not fall below a minimum value. Storage periods of 1 month, 3 months, 6 months and 8 months are defined.

Glycerol (meth)acrylate carboxylic esters are storage-stable in accordance with the invention if the threshold value does not fall below 85% by weight for diesters or exceed 3% by weight for triesters. It has been found, surprisingly, that with an excess of acid, the glycerol (meth)acrylate carboxylic esters are always storage-stable at 30° C. over the course of 8 months. If the storage is at 50° C., a storage stability of at least 3 months, preferably more than 6 months, especially preferably more than 8 months, can be achieved.

The molar ratio of acid to glycidyl (meth)acrylate may be adjusted to a ratio of from 1.001:1 to 5:1 by using appropriate amounts of carboxylic acids endogenous to the system. The molar ratio of carboxylic acid to glycidyl (meth)acrylate is preferably adjusted to a ratio of from 1.01:1 to 2:1, particularly preferably of from 1.02:1 to 1.5:1. These molar ratios are present in accordance with the invention at the end of the addition of the reactants.

It has been found, surprisingly, that independently of the molar ratio of carboxylic acid to glycidyl (meth)acrylate at the end of the addition of the reactants, a storage-stable glycerol (meth)acrylate carboxylic ester can be prepared by adjusting to a molar ratio of from 1.001:1 to 5:1 by addition of acids after the synthesis, in particular before storage. The molar ratio of acid to glycidyl (meth)acrylate is preferably adjusted to a ratio before storage of from 1.01:1 to 2:1, particularly preferably of from 1.02:1 to 1.5:1, optionally by addition of an acid.

It has been found that carboxylic acids endogenous to the system are suitable, but also carboxylic acids foreign to the system and Broensted acids foreign to the system may be added in order to set the required molar ratio of acid to glycidyl (meth)acrylate.

The molar content of acid in the end product must be greater than the molar content of glycidyl (meth)acrylate during storage.

The glycerol (meth)acrylate carboxylic ester is present as an isomeric mixture. The isomeric ratio is dependent on the reaction conditions. The epoxide ring opening shifts as a function of the reaction temperature and therefore influences the distribution of the isomers A and B of formula (I).

The reactants used are carboxylic acids of the formula (II).

R₁=H or CH₃, R₂=hydrogen, or aliphatic carbons with C1 to C30, or aliphatic cyclic carbon compounds having a ring size of C4 to C8, unsubstituted or substituted by N, S, O or P, or halogenated aliphatic carbon compounds with C1 to C8, or aromatic carbon compounds, or heteroaromatic carbon compounds substituted by N, S, O or P, or unsaturated aliphatic carbon compounds with C2 to C30.

The carboxylic acids of the formula (II) also include functionalized aliphatic carboxylic acids with functional groups selected from the group comprising hydroxides, nitriles, esters, amides, ketones, thiols and ethers.

Carboxylic acids from the following groups are suitable: hydroxycarboxylic acids, saturated carboxylic acids, unsaturated and polyunsaturated carboxylic acids, aromatic carboxylic acids, cyclic and heterocyclic carboxylic acids, heteroaromatic carboxylic acids and halogenated carboxylic acids.

Particular preference is given to carboxylic acids selected from the group comprising hydroxyisobutyric acid (HIBA), methacrylic acid, acrylic acid, acetic acid, butyric acid, stearic acid, benzoic acid, salicylic acid, nicotinic acid, proline, oleic acid, lactic acid and trichloroacetic acid.

The carboxylic acids are reacted with glycidyl (meth)acrylate. This notation signifies both glycidyl methacrylate and glycidyl acrylate.

The method is conducted at temperatures between 20 and 130° C., preferably at temperatures between 85 and 110° C.

At temperatures over 130° C., the acute risk of polymerization exists. Therefore, the carboxylic acid is preferably initially charged and the glycidyl (meth)acrylate is metered in such that the reaction temperature remains within the specified limits.

Carboxylic acids having melting points above the reaction temperature require the use of high-boiling solvents inert under the reaction conditions. Suitable solvents are toluene, dimethylformamide, nitrobenzene, dibutyl ether, chlorobenzene and further solvents from the group of high-boiling solvents.

The reaction is effected preferably in the presence of a catalyst.

Suitable catalysts are quaternary alkylammonium halides, triphenylphosphine, triphenylphosphine oxide, hexamethylenetetramine, tetramethylammonium bromide, tetrabutylammonium bromide, N,N-dimethylbenzylamine and active Cr(III) complexes.

Particular preference is given to using benzyltriethylammonium chloride, benzyltriethylammonium bromide, tetrabutylammonium chloride or tetrabutylammonium bromide.

EXAMPLES

The carboxylic acid, 0.05 g of hydroquinone monomethyl ether and 9.60 g of benzyltriethylammonium chloride as catalyst were initially charged and heated to 90° C. in a 1 l Witt's flask with oil circulation, bottom outlet valve, porcelain blade stirrer with stirrer motor, 500 ml addition funnel as well as a thermometer and air inlet. At 90-91° C., 300 g of glycidyl (meth)acrylate are added over a period of 60 minutes. At the end of the addition, the mixture is heated to 97° C., the temperature briefly increasing here to a maximum of 100° C. The mixture is maintained at 97° C. for 10 h, then cooled and discharged. From the product thus obtained, storage stability tests were carried out at 30 and 50° C. in order to establish the tendency of the product toward disproportionation.

Preparation Example 1

Method is distinguished in that 179 g of methacrylic acid is used as carboxylic acid.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 86.1% 81.7% 53.0% 48.7% 48.4% Triester content [%] max. 3.00  1.6%  5.4% 28.1% 33.3% 33.7% Methacrylic acid [%] 0.40% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.78% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 86.1% 49.0% 46.8% 47.2% 47.0% Triester content [%] max. 3.00  1.6% 31.9% 33.6% 33.8% 33.6% Methacrylic acid [%] 0.40% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.78% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 2

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 181.7 g of methacrylic acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 86.2% 81.8% 53.1% 48.8% 48.5% Triester content [%] max. 3.00  1.8%  6.1% 31.5% 37.4% 37.8% Methacrylic acid [%] 0.42% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.72% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 86.2% 49.1% 46.9% 47.2% 47.1% Triester content [%] max. 3.00  1.8% 35.8% 37.7% 37.9% 37.6% Methacrylic acid [%] 0.42% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.72% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 3

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 185.3 g of methacrylic acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 89.3% 90.0% 89.8% 89.9% 89.3% Triester content [%] max. 3.00  1.5%  1.5%  1.5%  1.6%  1.9% Methacrylic acid [%] 0.45% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.65% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 89.3% 89.4% 89.3% 88.7% 87.2% Triester content [%] max. 3.00  1.5%  1.7%  2.0%  2.6%  3.0% Methacrylic acid [%] 0.45% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.65% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 8 months.

Preparation Example 4

Method is distinguished in that the procedure is carried out analogously to Example 1 but 124.8 g of acetic acid is used as carboxylic acid.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 86.8% 82.4% 53.5% 49.1% 48.8% Triester content [%] max. 3.00  1.7%  5.8% 29.7% 35.3% 35.7% Acetic acid [%] 0.31% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.88% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 86.8% 49.5% 47.3% 47.6% 47.4% Triester content [%] max. 3.00  1.7% 33.8% 35.6% 35.8% 35.5% Acetic acid [%] 0.31% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.88% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 5

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 126.7 g of acetic acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 87.0% 82.5% 53.6% 49.2% 48.9% Triester content [%] max. 3.00  1.8%  6.1% 31.3% 37.2% 37.6% Acetic acid [%] 0.33% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.81% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 87.0% 49.6% 47.3% 47.7% 47.5% Triester content [%] max. 3.00  1.8% 35.7% 37.5% 37.7% 37.5% Acetic acid [%] 0.33% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.81% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 6

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 129.3 g of acetic acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 89.4% 90.1% 89.9% 90.0% 89.3% Triester content [%] max. 3.00  1.7%  1.8%  1.7%  1.9%  2.2% Acetic acid [%] 0.35% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.73% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 89.4% 89.5% 89.4% 88.8% 87.3% Triester content [%] max. 3.00  1.7%  2.1%  2.4%  3.0%  3.5% Acetic acid [%] 0.35% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.73% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 6 months.

Preparation Example 7

Method is distinguished in that the procedure is carried out analogously to Example 1 but 183.2 g of butyric acid is used as carboxylic acid.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 86.0% 81.6% 53.0% 48.7% 48.4% Triester content [%] max. 3.00  1.8%  6.2% 31.9% 37.9% 38.3% Butyric acid [%] 0.40% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.78% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 86.0% 49.0% 46.8% 47.1% 47.0% Triester content [%] max. 3.00  1.8% 36.3% 38.2% 38.4% 38.1% Butyric acid [%] 0.40% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.78% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 8

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 186 g of butyric acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 87.0% 82.6% 53.6% 49.3% 49.0% Triester content [%] max. 3.00  1.9%  6.4% 33.2% 39.4% 39.8% Butyric acid [%] 0.42% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.71% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.0% 49.6% 47.4% 47.7% 47.5% content [%] Triester max. 3.00 1.9% 37.8% 39.7% 39.9% 39.7% content [%] Butyric 0.42% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.71% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 9

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 189.7 g of butyric acid is used as carboxylic acid.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.9% 89.6% 89.4% 89.5% 88.9% content [%] Triester max. 3.00 1.7% 1.8% 1.7% 1.9% 2.2% content [%] Butyric 0.46% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.64% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.9% 89.1% 88.9% 88.4% 86.9% content [%] Triester max. 3.00 1.7% 2.0% 2.4% 3.0% 3.5% content [%] Butyric 0.46% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.64% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 6 months.

Preparation Example 10

Method is distinguished in that the procedure is carried out analogously to Example 1 but 591.4 g of stearic acid is used as carboxylic acid.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.0% 82.5% 53.5% 49.2% 48.9% content [%] Triester max. 3.00 1.3% 4.2% 21.7% 25.8% 26.1% content [%] Stearic 0.71% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.42% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.0% 49.6% 47.3% 47.7% 47.5% content [%] Triester max. 3.00 1.3% 24.7% 26.0% 26.2% 26.0% content [%] Stearic 0.71% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.42% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 11

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 600.4 g of stearic acid is used as carboxylic acid.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 86.2% 81.7% 53.0% 48.8% 48.5% content [%] Triester max. 3.00 1.7% 5.7% 29.4% 34.9% 35.2% content [%] Stearic 0.74% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.39% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 86.2% 49.1% 46.9% 47.2% 47.1% content [%] Triester max. 3.00 1.7% 33.4% 35.1% 35.3% 35.1% content [%] Stearic 0.74% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.39% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 12

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 612.4 g of stearic acid is used as carboxylic acid.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 86.9% 87.6% 87.4% 87.5% 86.9% content [%] Triester max. 3.00 1.6% 1.7% 1.6% 1.8% 2.0% content [%] Stearic 0.79% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.35% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 86.9% 87.1% 86.9% 86.4% 84.9% content [%] Triester max. 3.00 1.6% 1.9% 2.2% 2.8% 3.3% content [%] Stearic 0.79% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.35% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 6 months.

Preparation Example 13

Method is distinguished in that the procedure is carried out analogously to Example 1 but 253.9 g of benzoic acid is used as carboxylic acid.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 86.2% 81.8% 53.1% 48.8% 48.5% content [%] Triester max. 3.00 1.7% 5.8% 30.1% 35.7% 36.1% content [%] Benzoic 0.49% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.68% n.d. n.d. n.d. n.d. methacrylate %]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 86.2% 49.1% 46.9% 47.2% 47.1% content [%] Triester max. 3.00 1.7% 34.2% 36.0% 36.2% 36.0% content [%] Benzoic 0.49% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.68% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 14

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 257.7 g of benzoic acid is used as carboxylic acid.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.1% 83.6% 54.3% 49.9% 49.6% content [%] Triester max. 3.00 1.6% 5.4% 27.8% 33.1% 33.4% content [%] Benzoic 0.51% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.62% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.1% 50.2% 48.0% 48.3% 48.1% content [%] Triester max. 3.00 1.6% 31.7% 33.3% 33.5% 33.3% content [%] Benzoic 0.51% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.62% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 15

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 262.9 g of benzoic acid is used as carboxylic acid.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.3% 89.0% 88.8% 88.9% 88.3% content [%] Triester max. 3.00 1.2% 1.3% 1.2% 1.4% 1.6% content [%] Benzoic 0.55% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.56% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.3% 88.5% 88.3% 87.8% 86.3% content [%] Triester max. 3.00 1.2% 1.5% 1.7% 2.2% 2.5% content [%] Benzoic 0.55% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.56% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 8 months.

Preparation Example 16

Method is distinguished in that the procedure is carried out analogously to Example 1 but 287.1 g of salicylic acid as carboxylic acid and a solvent are used.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.7% 84.2% 54.6% 50.2% 49.9% content [%] Triester max. 3.00 1.4% 4.7% 24.1% 28.6% 28.9% content [%] Salicylic 0.52% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.64% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.7% 50.6% 48.3% 48.6% 48.5% content [%] Triester max. 3.00 1.4% 27.4% 28.8% 29.0% 28.8% content [%] Salicylic 0.52% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.64% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 17

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 291.5 g of salicylic acid as carboxylic acid and a solvent are used.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.6% 85.0% 55.2% 50.7% 50.4% content [%] Triester max. 3.00  1.8% 6.2% 32.0% 37.9% 38.4% content [%] Salicylic 0.55% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.59% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.6% 51.1% 48.8% 49.1% 48.9% content [%] Triester max. 3.00 1.8% 36.4% 38.2% 38.5% 38.2% content [%] Salicylic 0.55% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.59% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 18

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 297.3 g of salicylic acid as carboxylic acid and a solvent are used.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.7% 90.4% 90.2% 90.4% 89.7% content [%] Triester max. 3.00 1.4% 1.5% 1.4% 1.6% 1.8% content [%] Salicylic 0.59% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.53% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.7% 89.9% 89.7% 89.2% 87.7% content [%] Triester max. 3.00 1.4% 1.7% 2.0% 2.5% 2.9% content [%] Salicylic 0.59% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.53% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 8 months.

Preparation Example 19

Method is distinguished in that the procedure is carried out analogously to Example 1 but 255.9 g of nicotinic acid as carboxylic acid and a solvent are used.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.6% 83.1% 53.9% 49.6% 49.3% content [%] Triester max. 3.00 1.6% 5.4% 27.9% 33.1% 33.5% content [%] Nicotinic 0.49% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.67% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.6% 49.9% 47.7% 48.0% 47.8% content [%] Triester max. 3.00 1.6% 31.7% 33.4% 33.5% 33.3% content [%] Nicotinic 0.49% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.67% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 20

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 259.8 g of nicotinic acid as carboxylic acid and a solvent are used.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.0% 82.5% 53.6% 49.2% 48.9% content [%] Triester max. 3.00 1.8% 5.9% 30.7% 36.5% 36.9% content [%] Nicotinic 0.51% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.62% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.0% 49.6% 47.3% 47.7% 47.5% content [%] Triester max. 3.00 1.8% 35.0% 36.8% 37.0% 36.7% content [%] Nicotinic 0.51% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.62% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 21

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 265 g of nicotinic acid as carboxylic acid and a solvent are used.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.2% 89.9% 89.7% 89.8% 89.2% content [%] Triester max. 3.00 2.0% 2.0% 2.0% 2.2% 2.5% content [%] Nicotinic 0.55% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.56% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.2% 89.3% 89.2% 88.6% 87.1% content [%] Triester max. 3.00 2.0% 2.3% 2.7% 3.0% 3.7% content [%] Nicotinic 0.55% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.56% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 6 months.

Preparation Example 22

Method is distinguished in that the procedure is carried out analogously to Example 1 but 239.3 g of proline as carboxylic acid and a solvent are used.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.6% 84.1% 54.6% 50.2% 49.9% content [%] Triester max. 3.00 1.9% 6.3% 32.6% 38.7% 39.1% content [%] Proline [%] 0.47% n.d. n.d. n.d. n.d. Glycidyl 0.70% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.6% 50.5% 48.2% 48.6% 48.4% content [%] Triester max. 3.00 1.9% 37.1% 39.0% 39.2% 39.0% content [%] Proline [%] 0.47% n.d. n.d. n.d. n.d. Glycidyl 0.70% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 23

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 243 g of proline as carboxylic acid and a solvent are used.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.0% 84.4% 54.8% 50.4% 50.1% content [%] Triester max. 3.00 1.8% 5.9% 30.3% 36.0% 36.3% content [%] Proline [%] 0.50% n.d. n.d. n.d. n.d. Glycidyl 0.64% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.0% 50.7% 48.4% 48.8% 48.6% content [%] Triester max. 3.00 1.8% 34.5% 36.2% 36.4% 36.2% content [%] Proline [%] 0.50% n.d. n.d. n.d. n.d. Glycidyl 0.64% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 24

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 247.8 g of proline as carboxylic acid and a solvent are used.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 85.6% 86.3% 86.1% 86.2% 85.6% content [%] Triester max. 3.00 1.1% 1.1% 1.1% 1.2% 1.4% content [%] Proline [%] 0.53% n.d. n.d. n.d. n.d. Glycidyl 0.58% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 85.6% 85.7% 85.6% 85.1% 83.6% content [%] Triester max. 3.00 1.1% 1.3% 1.5% 1.9% 2.2% content [%] Proline [%] 0.53% n.d. n.d. n.d. n.d. Glycidyl 0.58% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 6 months.

Preparation Example 25

Method is distinguished in that the procedure is carried out analogously to Example 1 but 149.8 g of acrylic acid is used as carboxylic acid.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.0% 84.4% 54.8% 50.4% 50.1% content [%] Triester max. 3.00 1.4% 4.6% 23.8% 28.3% 28.6% content [%] Acrylic 0.36% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.83% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.0% 50.7% 48.4% 48.8% 48.6% content [%] Triester max. 3.00 1.4% 27.1% 28.5% 28.7% 28.5% content [%] Acrylic 0.36% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.83% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 26

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 152.1 g of acrylic acid is used as carboxylic acid.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.2% 83.7% 54.3% 49.9% 49.6% content [%] Triester max. 3.00 1.8% 6.0% 30.9% 36.7% 37.1% content [%] Acrylic 0.37% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.77% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.2% 50.3% 48.0% 48.3% 48.2% content [%] Triester max. 3.00 1.8% 35.2% 37.0% 37.2% 36.9% content [%] Acrylic 0.37% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.77% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 27

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 155.1 g of acrylic acid is used as carboxylic acid.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.3% 89.0% 88.8% 88.9% 88.3% content [%] Triester max. 3.00 1.8% 1.9% 1.8% 2.0% 2.3% content [%] Acrylic 0.40% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.69% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 88.3% 88.4% 88.3% 87.7% 86.2% content [%] Triester max. 3.00 1.8% 2.2% 2.4% 2.7% 3.0% content [%] Acrylic 0.40% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.69% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 8 months.

Preparation Example 28

Method is distinguished in that the procedure is carried out analogously to Example 1 but 587.2 g of oleic acid is used as carboxylic acid.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.6% 83.1% 53.9% 49.6% 49.3% content [%] Triester max. 3.00 1.2% 4.1% 21.4% 25.4% 25.6% content [%] Oleic 0.71% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.42% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.6% 49.9% 47.7% 48.0% 47.8% content [%] Triester max. 3.00 1.2% 24.3% 25.6% 25.7% 25.5% content [%] Oleic 0.71% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.42% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 29

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 596.1 g of oleic acid is used as carboxylic acid.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.1% 84.6% 54.9% 50.4% 50.2% content [%] Triester max. 3.00 1.1% 3.8% 19.7% 23.4% 23.7% content [%] Oleic 0.74% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.39% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 89.1% 50.8% 48.5% 48.8% 48.7% content [%] Triester max. 3.00 1.1% 22.5% 23.6% 23.8% 23.6% content [%] Oleic 0.74% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.39% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 30

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 608 g of oleic acid is used as carboxylic acid.

Storage stability at 30° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.7% 88.4% 88.2% 88.3% 87.7% content [%] Triester max. 3.00 1.4% 1.4% 1.4% 1.5% 1.8% content [%] Oleic 0.79% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.35% n.d. n.d. n.d. n.d. methacrylate [%]

Storage stability at 50° C. 1 3 6 8 Start month months months months Diester min. 85.00 87.7% 87.8% 87.7% 87.1% 85.7% content [%] Triester max. 3.00 1.4% 1.7% 1.9% 2.4% 2.8% content [%] Oleic 0.79% n.d. n.d. n.d. n.d. acid [%] Glycidyl 0.35% n.d. n.d. n.d. n.d. methacrylate [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 8 months.

Preparation Example 31

Method is distinguished in that the procedure is carried out analogously to Example 1 but 187.3 g of lactic acid is used as carboxylic acid.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 89.0% 84.4% 54.8% 50.4% 50.1% Triester content [%] max. 3.00  1.0%  3.5% 18.0% 21.4% 21.7% Lactic acid [%] 0.41% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.77% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 89.0% 50.7% 48.4% 48.8% 48.6% Triester content [%] max. 3.00  1.0% 20.5% 21.6% 21.7% 21.6% Lactic acid [%] 0.41% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.77% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 32

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 190.1 g of lactic acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 89.3% 84.8% 55.0% 50.6% 50.3% Triester content [%] max. 3.00  1.6%  5.2% 27.0% 32.1% 32.4% Lactic acid [%] 0.43% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.71% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 89.3% 50.9% 48.6% 49.0% 48.8% Triester content [%] max. 3.00  1.6% 30.8% 32.3% 32.5% 32.3% Lactic acid [%] 0.43% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.71% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 33

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 193.9 g of lactic acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 85.6% 86.3% 86.1% 86.2% 85.6% Triester content [%] max. 3.00  1.4%  1.4%  1.4%  1.5%  1.7% Lactic acid [%] 0.46% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.64% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 85.6% 85.7% 85.6% 85.1% 83.6% Triester content [%] max. 3.00  1.4%  1.6%  1.9%  2.4%  2.8% Lactic acid [%] 0.46% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.64% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 6 months.

Preparation Example 34

Method is distinguished in that the procedure is carried out analogously to Example 1 but 216.4 g of hydroxyisobutyric acid is used as carboxylic acid.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 87.0% 82.5% 53.6% 49.2% 48.9% Triester content [%] max. 3.00  1.7%  5.8% 30.2% 35.9% 36.2% Hydroxyisobutyric acid [%] 0.45% n.d. n.d. n.d. n.d. Glycidyl methacrylate [%] 0.73% n.d. n.d. n.d. n.d.

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 87.0% 49.6% 47.4% 47.7% 47.5% Triester content [%] max. 3.00  1.7% 34.4% 36.1% 36.3% 36.1% Hydroxyisobutyric acid [%] 0.45% n.d. n.d. n.d. n.d. Glycidyl methacrylate [%] 0.73% n.d. n.d. n.d. n.d.

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 35

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 219.7 g of hydroxyisobutyric acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 87.4% 83.0% 53.8% 49.5% 49.2% Triester content [%] max. 3.00  1.3%  4.4% 22.6% 26.8% 27.1% Hydroxyisobutyric acid [%] 0.47% n.d. n.d. n.d. n.d. Glycidyl methacrylate [%] 0.67% n.d. n.d. n.d. n.d.

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 87.4% 49.8% 47.6% 47.9% 47.8% Triester content [%] max. 3.00  1.3% 25.7% 27.0% 27.2% 27.0% Hydroxyisobutyric acid [%] 0.47% n.d. n.d. n.d. n.d. Glycidyl methacrylate [%] 0.67% n.d. n.d. n.d. n.d.

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 36

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 224.1 g of hydroxyisobutyric acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 88.1% 88.8% 88.6% 88.7% 88.1% Triester content [%] max. 3.00  1.7%  1.7%  1.7%  1.9%  2.1% Hydroxyisobutyric acid [%] 0.50% n.d. n.d. n.d. n.d. Glycidyl methacrylate [%] 0.60% n.d. n.d. n.d. n.d.

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 88.1% 88.2% 88.1% 87.5% 86.0% Triester content [%] max. 3.00  1.7%  2.0%  2.3%  3.0%  3.4% Hydroxyisobutyric acid [%] 0.50% n.d. n.d. n.d. n.d. Glycidyl methacrylate [%] 0.60% n.d. n.d. n.d. n.d.

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 6 months.

Preparation Example 37

Method is distinguished in that the procedure is carried out analogously to Example 1 but 339.7 g of trichloroacetic acid is used as carboxylic acid.

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:0.985

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 87.5% 83.0% 53.9% 49.5% 49.2% Triester content [%] max. 3.00  1.4%  4.8% 25.0% 29.7% 30.0% Trichloroacetic acid [%] 0.57% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.59% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 87.5% 49.8% 47.6% 47.9% 47.8% Triester content [%] max. 3.00  1.4% 28.4% 29.9% 30.1% 29.9% Trichloroacetic acid [%] 0.57% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.59% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:0.985 at the end of the reactant addition proved to be NOT         storage-stable!

Preparation Example 38

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1

Method is distinguished in that the procedure is carried out analogously to Example 1 but 344.8 g of trichloroacetic acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 88.0% 83.5% 54.2% 49.8% 49.5% Triester content [%] max. 3.00  1.7%  5.8% 29.9% 35.5% 35.9% Trichloroacetic acid [%] 0.59% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.54% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 88.0% 50.1% 47.9% 48.2% 48.0% Triester content [%] max. 3.00  1.7% 34.1% 35.8% 36.0% 35.8% Trichloroacetic acid [%] 0.59% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.54% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition proved to be NOT         storage-stable!

Inventive Example 39

Molar stoichiometry (glycidyl methacrylate:carboxylic acid) 1:1.02

Method is distinguished in that the procedure is carried out analogously to Example 1 but 351.7 g of trichloroacetic acid is used as carboxylic acid.

Storage stability at 30° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 85.6% 86.3% 86.1% 86.2% 85.6% Triester content [%] max. 3.00  1.6%  1.6%  1.6%  1.8%  2.0% Trichloroacetic acid [%] 0.64% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.48% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. Start 1 month 3 months 6 months 8 months Diester content [%] min. 85.00 85.6% 85.7% 85.6% 85.1% 83.6% Triester content [%] max. 3.00  1.6%  1.9%  2.2%  2.8%  3.3% Trichloroacetic acid [%] 0.64% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.48% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1.02 at the end of the reactant addition had a storage         stability of more than 3 months.

Inventive Example 40

Post-Stablization with Carboxylic Acid Endogenous to the System Prior to Storage

Method according to Example 1, distinguished in that 179 g of methacrylic acid is used as carboxylic acid and at the end of the reactant addition the molar stoichiometry (glycidyl methacrylate:carboxylic acid) is 1:0.985.

Prior to storage, the crude product obtained is doped with 1.5 g of methacrylic acid.

Molar stoichiometry prior to storage: glycidyl methacrylate<carboxylic acid

Storage stability at 30° C. 1 3 6 Product Start month months months 8 months Diester content [%] min. 86.10% 85.84% 86.47% 86.28% 86.39% 85.77% 85.00 Triester content [%] max. 1.60% 1.59%  1.58%  1.53%  1.69%  1.94% 3.00 Methacrylic acid [%] 0.40% 0.71% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.78% 0.78% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. 1 3 6 Product Start month months months 8 months Diester content [%] min. 86.10% 85.84% 85.94% 85.81% 85.26% 83.81% 85.00 Triester content [%] max 1.60% 1.59%  1.82%  2.10%  2.68%  3.12% 3.00 Methacrylic acid [%] 0.40% 0.71% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.78% 0.78% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The crude product prepared with a molar         stoichiometry of 1:0.985 at the end of the reactant addition,         but post-stabilized, had a storage stability of 6 months,         whereas the non-stabilized reference sample of Example 1 was not         storage-stable.

Inventive Example 41

Post-Stablization with Carboxylic Acid Endogenous to the System Prior to Storage

Method according to Example 2, distinguished in that 181.7 g of methacrylic acid is used as carboxylic acid and at the end of the reactant addition the molar stoichiometry (glycidyl methacrylate:carboxylic acid) was 1:1.

Prior to storage, the crude product obtained is doped with 1.1 g of methacrylic acid.

Molar stoichiometry prior to storage: glycidyl methacrylate<carboxylic acid

Storage stability at 30° C. 3 Product Start 1 month months 6 months 8 months Diester content [%] min. 86.20% 86.00% 86.67% 86.49% 86.59% 85.97% 85.00 Triester content [%] max. 1.80% 1.80%  1.67%  1.62%  1.78%  2.05% 3.00 Methacrylic acid [%] 0.42% 0.65% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.72% 0.72% n.d. n.d. n.d. n.d. [%]

Storage stability at 50° C. 3 Product Start 1 month months 6 months 8 months Diester content [%] min. 86.20% 86.00% 86.14% 86.01% 85.46% 84.00% 85.00 Triester content [%] max. 1.80% 1.80%  1.92%  2.22%  2.83%  3.30% 3.00 Methacrylic acid [%] 0.42% 0.65% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.72% 0.72% n.d. n.d. n.d. n.d. [%]

-   -   Conclusion: The crude product prepared with a molar         stoichiometry of 1:1 at the end of the reactant addition, but         post-stabilized had a storage stability of 6 months, whereas the         non-stabilized reference sample of Example 2 was not         storage-stable.

Inventive Example 42

Post-Stabilization with a Carboxylic Acid Foreign to the System Prior to Storage

Method according to Example 1, distinguished in that 179 g of methacrylic acid is used as carboxylic acid and at the end of the reactant addition the molar stoichiometry (glycidyl methacrylate:carboxylic acid) was 1:0.985.

Prior to storage, the crude product obtained is doped with 0.8 g of formic acid.

Molar stoichiometry prior to storage: glycidyl methacrylate<carboxylic acid

Storage stability at 30° C. 1 3 8 Product Start month months 6 months months Diester content [%] min. 86.1% 86.0% 86.2% 86.0% 86.1% 85.5% 85.00 Triester content [%] max. 1.60% 1.59% 1.18% 1.15% 1.26% 1.45% 3.00 Methacrylic acid [%] 0.40% 0.40% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.78% 0.78% n.d. n.d. n.d. n.d. [%] Formic acid [%] 0.00% 0.16% n.d. n.d. n.d. n.d.

Storage stability at 50° C. 1 3 8 Product Start month months 6 months months Diester content [%] min 86.1% 85.8% 85.6% 85.5% 85.0% 83.5% 85.00 Triester content [%] max. 1.60% 1.59% 1.36% 1.57% 2.01% 2.34% 3.00 Methacrylic acid [%] 0.40% 0.71% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.78% 0.78% n.d. n.d. n.d. n.d. [%] Formic acid [%] 0.00% 0.16% n.d. n.d. n.d. n.d.

-   -   Conclusion: The crude product prepared with a molar         stoichiometry of 1:0.985 at the end of the reactant addition,         but post-stabilized with formic acid as acid foreign to the         system had a storage stability of 6 months, whereas the         non-stabilized reference sample of Example 1 was not         storage-stable.

Inventive Example 43

Post-Stablization with Carboxylic Acid Foreign to the System Prior to Storage

Method according to Example 2, distinguished in that 181.7 g of methacrylic acid is used as carboxylic acid and at the end of the reactant addition the molar stoichiometry (glycidyl methacrylate:carboxylic acid) was 1:1.

Prior to storage, the crude product obtained is doped with 0.6 g of formic acid.

Molar stoichiometry prior to storage: glycidyl methacrylate<carboxylic acid

Storage stability at 30° C. Product Start 1 month 3 months 6 months 8 months Diester content [%] min. 86.20% 86.06% 86.67% 86.49% 86.59% 85.97% 85.00 Triester content [%] max. 1.80% 1.79%  1.67%  1.62%  1.78%  2.05% 3.00 Methacrylic acid [%] 0.42% 0.65% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.72% 0.72% n.d. n.d. n.d. n.d. [%] Formic acid [%] 0.00% 0.12% n.d. n.d. n.d. n.d.

Storage stability at 50° C. Product Start 1 month 3 months 6 months 8 months Diester content [%] min. 86.20% 86.00% 86.14% 86.01% 85.46% 84.00% 85.00 Triester content [%] max. 1.80% 1.79%  1.92%  2.22%  2.83%  3.30% 3.00 Methacrylic acid [%] 0.42% 0.65% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.72% 0.72% n.d. n.d. n.d. n.d. [%] Formic acid [%] 0.00% 0.12% n.d. n.d. n.d. n.d.

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition, but the crude product         post-stabilized with formic acid as acid foreign to the system         had a storage stability of 6 months, whereas the non-stabilized         reference sample of Example 2 was not storage-stable.

Inventive Example 44

Post-Stablization with a Broensted Acid Prior to Storage

Method according to Example 1, distinguished in that 179 g of methacrylic acid is used as carboxylic acid and at the end of the reactant addition the molar stoichiometry (glycidyl methacrylate:carboxylic acid) was 1:0.985.

Prior to storage, the crude product obtained is doped with 0.55 g of phosphoric acid.

Molar stoichiometry prior to storage: glycidyl methacrylate<acid

Storage stability at 30° C. Product Start 1 month 3 months 6 months 8 months Diester content [%] min. 86.1% 86.0% 86.2% 86.0% 86.1% 85.5% 85.00 Triester content [%] max. 1.60% 1.59% 1.18% 1.15% 1.26% 1.45% 3.00 Methacrylic acid [%] 0.40% 0.40% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.78% 0.78% n.d. n.d. n.d. n.d. [%] Phosphoric acid [%] 0.00% 0.11% n.d. n.d. n.d. n.d.

Storage stability at 50° C. Product Start 1 month 3 months 6 months 8 months Diester content [%] min. 86.1% 86.0% 85.6% 85.5% 85.0% 83.5% 85.00 Triester content [%] max. 1.60% 1.59% 1.36% 1.57% 2.01% 2.34% 3.00 Methacrylic acid [%] 0.40% 0.71% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.78% 0.78% n.d. n.d. n.d. n.d. [%] Phosphoric acid [%] 0.00% 0.11% n.d. n.d. n.d. n.d.

-   -   Conclusion: The crude product prepared with a molar         stoichiometry of 1:0.985 at the end of the reactant addition,         but post-stabilized with phosphoric acid as inorganic acid         foreign to the system had a storage stability of 6 months,         whereas the non-stabilized reference sample of Example 1 was not         storage-stable.

Inventive Example 45

Post-Stablization with a Broensted Acid Prior to Storage

Method according to Example 2, distinguished in that 181.7 g of methacrylic acid is used as carboxylic acid and at the end of the reactant addition the molar stoichiometry (glycidyl methacrylate:carboxylic acid) was 1:1.

Prior to storage, the crude product obtained is doped with 0.25 g of phosphoric acid.

Molar stoichiometry prior to storage: glycidyl methacrylate<acid

Storage stability at 30° C. 1 8 Product Start month 3 months 6 months months Diester content [%] min. 86.20% 86.06% 86.67% 86.49% 86.59% 85.97% 85.00 Triester content [%] max. 1.80% 1.79%  1.67%  1.62%  1.78%  2.05% 3.00 Methacrylic acid [%] 0.42% 0.65% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.72% 0.72% n.d. n.d. n.d. n.d. [%] Phosphoric acid [%] 0.00% 0.05% n.d. n.d. n.d. n.d.

Storage stability at 50° C. 1 8 Product Start month 3 months 6 months months Diester content [%] min. 86.20% 86.06% 86.14% 86.01% 85.46% 84.00% 85.00 Triester content [%] max. 1.80% 1.79%  1.92%  2.22%  2.83%  3.30% 3.00 Methacrylic acid [%] 0.42% 0.65% n.d. n.d. n.d. n.d. Glycidyl methacrylate 0.72% 0.72% n.d. n.d. n.d. n.d. [%] Phosphoric acid [%] 0.00% 0.05% n.d. n.d. n.d. n.d.

-   -   Conclusion: The product prepared with a molar stoichiometry of         1:1 at the end of the reactant addition, but the crude product         post-stabilized with phosphoric acid as inorganic acid foreign         to the system had a storage stability of 6 months, whereas the         non-stabilized reference sample of Example 2 was not         storage-stable. 

The invention claimed is:
 1. A method for preparing storage-stable glycerol (meth)acrylate carboxylic esters of formula (I):

wherein: R₁=H or CH₃; R₂=hydrogen; a C1 to C30 aliphatic group optionally with a hydroxyl substituent; an aliphatic cyclic group with a C4 to C8 ring unsubstituted or substituted by N, S, O or P; a C1 to C8 halogenated aliphatic group; an aromatic group having a ring with five or six carbons and optionally with a hydroxyl substituent; a heteroaromatic group substituted by N, S, O or P and having a ring with five or six carbons; or a C2 to C30 unsaturated aliphatic group; said method comprising the steps of: a) reacting carboxylic acids of formula (II) with glycidyl (meth)acrylate at a temperature of 20-130° C. in the presence of a catalyst, by initially charging the carboxylic acids of formula (II) and adding glycidyl (meth)acrylate continuously, wherein the carboxylic acids of formula (II) have the structure:

wherein R₂=hydrogen; a C1 to C30 aliphatic group optionally with a hydroxyl substituent; an aliphatic cyclic group with a C4 to C8 ring unsubstituted or substituted by N, S, O or P; a C1 to C8 halogenated aliphatic group; an aromatic group having a ring with five or six carbons and optionally with a hydroxyl substituent; a heteroaromatic group substituted by N, S, O or P and having a ring with five or six carbons; or a C2 to C30 unsaturated aliphatic group; b) optionally, after the reaction is complete and prior to storage, adding foreign carboxylic acids of formula (III) and/or foreign Broensted acids, wherein the carboxylic acids of formula (III) have the structure:

wherein R₃ is defined as for R₂; c) storing the storage stable glycerol (meth)acrylate carboxylic esters of formula (I) with the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula III and foreign Broensted acids; wherein, at the beginning of storage, the sum total of the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula (III) and foreign Broensted acids is in molar excess to the glycidyl (meth)acrylate present.
 2. The method of claim 1, wherein the molar ratio of the sum total of the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula (III) and foreign Broensted acids to glycidyl (meth)acrylate is from 1.001:1 to 5:1.
 3. The method of claim 1, wherein the molar ratio of the sum total of the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula (III) and foreign Broensted acids to glycidyl (meth)acrylate is from 1.01:1 to 2:1.
 4. The method of claim 1, wherein the molar ratio of endogenous carboxylic acids of formula (II) to glycidyl (meth)acrylate at the end of the reaction is above 1:1 and neither foreign carboxylic acids of formula (III) nor foreign Broensted acids are added prior to storage.
 5. The method of claim 1, wherein the molar ratio of endogenous carboxylic acids of formula (II) to glycidyl (meth)acrylate, at the end of the reaction is below 1:1 but is adjusted to greater than 1:1 by addition of foreign carboxylic acids (III) and/or Broensted acids prior to storage.
 6. The method of claim 1, wherein the molar ratio of endogenous carboxylic acids of formula (II) to glycidyl (meth)acrylate, at the end of the reaction is below 1:1 but is adjusted to greater than 1:1 by addition of carboxylic acids (III) without Broensted acids.
 7. The method of claim 1, wherein the molar stoichiometry (glycidyl methacrylate: carboxylic acid) during the reaction is at least 1.02:1.
 8. The method of claim 1, wherein glycidyl (meth)acrylate and carboxylic acid (II) are reacted in the presence of catalytic amounts of a quaternary alkylammonium halide.
 9. The method of claim 8, wherein the quaternary alkylammonium halide is benzyltriethylammonium chloride.
 10. The method of claim 1, wherein, in step c), the glycerol (meth)acrylate carboxylic esters of formula (I) are stored for a period of at least three months at a temperature of up to 50° C. and maintain a diester content of 85% or greater and a triester content of 3% or less.
 11. The method of claim 1, wherein, in step c), the glycerol (meth)acrylate carboxylic esters of formula (I) are stored for a period of at least six months at a temperature of up to 30° C. and maintain a diester content of 85% or greater and a triester content of 3% or less.
 12. The method of claim 1, wherein R₂ is a C1 to C30 aliphatic group, or an aliphatic cyclic group with a C4 to C8 ring, unsubstituted or substituted by N, S, O or P.
 13. The method of claim 1, wherein R₂ is an aromatic group having a ring with up to six carbons or a heteroaromatic group substituted by N, S, O or P and having a ring with up to six carbons, or a C2 to C30 unsaturated aliphatic group.
 14. The method of claim 2, wherein glycidyl (meth)acrylate and endogenous carboxylic acids of formula (II) are reacted in the presence of catalytic amounts of a quaternary alkylammonium halide.
 15. The method of claim 14, wherein the quaternary alkylammonium halide is benzyltriethylammonium chloride.
 16. The method of claim 15, wherein, in step c), the glycerol (meth)acrylate carboxylic esters of formula (I) are stored for a period of at least three months at a temperature of up to 50° C. and maintain a diester content of 85% or greater and a triester content of 3% or less.
 17. A method for preparing storage-stable glycerol (meth)acrylate carboxylic esters of formula (I):

wherein: R₁=H or CH₃; R₂=hydrogen; a C1 to C30 aliphatic group optionally with a hydroxyl substituent; an aliphatic cyclic group with a C4 to C8 ring unsubstituted or substituted by N, S, O or P; a C1 to C8 halogenated aliphatic group; an aromatic group having a ring with five or six carbons and optionally with a hydroxyl substituent; a heteroaromatic group substituted by N, S, 0 or P and having a ring with five or six carbons; or a C2 to C30 unsaturated aliphatic group; said method comprising: a) making the storage-stable glycerol (meth)acrylate carboxylic esters of formula (I) by a procedure consisting essentially of reacting carboxylic acids of formula (II) with glycidyl (meth)acrylate at a temperature of 20-130° C. in the presence of a catalyst, wherein the carboxylic acids of formula (II) have the structure:

R₂=hydrogen; a C1 to C30 aliphatic group optionally with a hydroxyl substituent; an aliphatic cyclic group with a C4 to C8 ring unsubstituted or substituted by N, S, O or P; a C1 to C8 halogenated aliphatic group; an aromatic group having a ring with five or six carbons and optionally with a hydroxyl substituent; a heteroaromatic group substituted by N, S, or P and having a ring with five or six carbons; or a C2 to C30 unsaturated aliphatic group; b) optionally, after the reaction of step a) is complete and prior to storage, adding foreign carboxylic acids of formula (III) and/or foreign Broensted acids, wherein the carboxylic acids of formula (III) have the structure:

wherein R₃ is defined as for R₂; c) storing the storage stable glycerol (meth)acrylate carboxylic esters of formula (I) with the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula III and foreign Broensted acids; wherein, at the beginning of storage, the sum total of the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula (III) and foreign Broensted acids is in molar excess to the glycidyl (meth)acrylate present.
 18. The method of claim 1, wherein the carboxylic acids of formulas II and III are selected from the group consisting of: acetic acid, butyric acid, stearic acid, benzoic acid, salicylic acid, nicotinic acid, proline, acrylic acid, oleic acid, lactic acid, hydroxyisobutyric acid, trichloroacetic acid, or methacrylic acid.
 19. The method of claim 1, wherein the molar ratio of the sum total of the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula (III) and foreign Broensted acids to glycidyl (meth)acrylate is from 1.01:1 to 5:1.
 20. The method of claim 1, wherein foreign carboxylic acids of formula (III) and/or foreign Broensted acids are added in step b) prior to storage. 